1. Technical Field
The present disclosure relates to a calibration device, a calibration method, and a program used for calibrating of at least one projection display device that projects an image on a projection plane. The present disclosure also relates to a projection display device having such a calibration device. The present disclosure also relates to a projection display system having such a calibration device and a projection display device.
2. Description of Related Art
A projection display device that projects an image on a projection plane, in its initial set-up, undergoes calibration so that image projection is fitted within a projection range of the projection plane. However, a deviation of the relative position between the projection plane and the projection display device can occur when a time has passed after the calibration. Therefore, the projection display device has to be regularly recalibrated. To detect the positional deviation, i.e., to measure the relative position or a positional change between the projection plane and the projection display device, a sensor, for example, an imaging device and a distance measuring sensor may be used.
According to a multi-projection system—in which an image is formed by images projected by a plurality of projectors—disclosed by Japanese Unexamined Patent Application Publication No. 2006-304100, a geometrical deviation between the images projected by the projectors is detected and then recalibrated. Specifically, in measurement by a distance measuring sensor, if the currently measured relative position does not agree with the previously measured relative position, the system determines that the image formed on the screen has a geometrical deviation. If the geometrical deviation is detected, the system performs recalibration and forms a corrected image on the screen using a calculated correction value.
According to the disclosure of Japanese Unexamined Patent Application Publication No. 2006-304100, however, deviation that can be caused by the distance measuring sensor itself is not taken into consideration. That is, the detected relative position itself can contain an error.
To address the problem above, the present disclosure provides a calibration device for a projection display device capable of recalibrating a deviation of the relative position between the projection plane and the projection display device detected after calibration of the projection display device, while taking a deviation of the sensor itself into consideration. The present disclosure provides a calibration method and a program of the aforementioned calibration devise. It also provides a projection display device having the aforementioned calibration device. It also provides a projection display system having the aforementioned calibration device and the projection display device.